Marine toxins pose a threat to public health and the seafood industry. One such toxin, isolated from oysters near New Zealand, is gymnodimine 1.Proposed is a total synthesis of this compound featuring a potential biosynthetic pathway - an intramolecular macrocyclization via a Diels- Alder reaction. Macrocyclization via the Diels-Alder reaction is a potentially useful method in organic synthesis, but has been little studied. The proposed synthesis should provide ample quantities of the Diels-Alder precursor, and an opportunity to study this transformation in detail. In addition, chemical synthesis would provide authentic material for the study of the heretofore undefined pharmacology of this neurotoxin. Moreover, chemical synthesis can provide structural analogues for potential use in the treatment of humans afflicted by this toxin.